A DMG (Disk Image) file is a type of file that contains a compressed disk image of a macOS installer. In the case of MacOS High Sierra 10.13.1 DMG, it's a file that contains the installation files for MacOS High Sierra version 10.13.1. This file can be used to create a bootable installer or to install the operating system directly on a Mac.
: Resolved issues where Bluetooth might appear unavailable during Apple Pay transactions and fixed Spotlight keyboard input bugs. System Requirements for macOS High Sierra
date 1020150017